There are lots of agreeable things about making your living as a writer from a young age. For instance, you never have to work a day in your life, as the saying goes about doing something you love.

The only downside I can think of — and it’s definitely a piece-of-grit-in-the-eye downside rather than a clothes-rending where-did-I-go-wrong downside — is that the geek chorus will always be moaning that you weren’t as good as you used to be.

I was reminded of this when a friend sent me a tweet at the weekend: “Sad to see once-cool punk journalist Julie Burchill supporting Israeli apartheid @EcostreamStore in Brighton today #Uncool.”

Even sadder, I’d say, to grade political activism as “cool” or “uncool”; definitely Adrian Mole territory.

As for me — yes, it’s tragic beyond belief that I am now a 54-year-old adult known for supporting a country I genuinely love rather than a 17-year-old known for pretending to like a dumb, very white type of music just so I could grab my one chance to become a writer on the New Musical Express.

Furthermore, far from selling out my younger self, I felt that I had travelled back in time last Saturday afternoon when I joined my regular rainbow coalition of Jews, atheists, Christians, Communists, gay people and even the odd ecologist to support the right of a Jewish business — the Ecostream shop in Brighton — to trade unhindered by hatred.

Suddenly I was back in the Lewisham of the summer of 1977, standing with the crowd who showed up to defy the National Front, and in front of me an old man who shouted “Jew-baiters! Damn Jew-baiters!”

These days the Jew-baiters wear left-wing drag and pretend to care about Third World rights — but they are still the same old Jew-haters, just with a fresh’n’funky style-up.

They love to drape themselves in the keffiyeh scarf — “a fetish”, my comrade Ben Marshall told me, that “the feminist Oriana Fallaci compared to Nazis draping themselves with the swastika — I assume it provides a similar sexual thrill.”

Exotic drapes aside, it’s interesting that whereas our side is so very varied, their side is so white and middle-class.

(And in the age-old tradition of patronising white liberals, they do of course know what is better for Arab Israelis and Palestinians than the Arab Israelis and Palestinians themselves who choose to work in the Ecostream factory in Mishor Adumim for a higher-than-average salary.)

Though they do, predictably, parade around a couple of self-loathing Jews of the type Howard Jacobson so savagely spiked in his Man Booker winning novel, The Finkler Question.

If these men were women, they’d be writing love letters to serial sex-murderers on Death Row; as it is, they get their kicks from drooling over the Hamas Charter.

Oh yes, they’re charmers, the other side. Last December, one of them – a 23-year-old “charity worker” — pleaded guilty to racially or religiously aggravated harassment at Brighton Magistrates’ Court after giving our side a Hitler salute and goose-stepping; mocking the working-class voices and gay sexualities of we Ecostream supporters is commonplace from them.

But there are some lovely moments. Last month a beautiful young man wearing a BDS (boycott, divestment, sanctions) sweatshirt crossed over to us and said simply: “What’s your side?”

After listening in silence to my comrade Ben’s explanation, he returned to the BDS mob, pulled off his sweatshirt, dropped it at their astonished feet and crossed back to stand with us for a while before going on his way.

As for me, far from feeling that I’ve strayed a long way from my teenage beliefs, I just smile, wave my Israeli flag proudly and recall who I dedicated my first book to: Menachem Begin, when I was just 18 years old. I knew what I believed then, and I know what I believe now.

The enemy may dress differently, but in the faces of the BDS crowd, I see the same ignorance and evil as I saw in the faces of the National Front, all those years ago.